<!DOCTYPE html>
<html>

<head>
	<meta charset="utf-8" />
	<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1,maximum-scale=1,user-scalable=no" />
	<title>下载</title>
</head>

<body>
	<a  id="iphone" onclick="window.open('https://static.bootcss.com/www/assets/img/yarn.png?1508511738690')"></a>
	<a  id="other" onclick="window.open('https://static.bootcss.com/www/assets/img/yarn.png?1508511738690')"></a>
</body>
<script src="https://cdn.bootcss.com/jquery/2.2.2/jquery.min.js"></script>
<script type="text/javascript">
	var ua = window.navigator.userAgent.toLocaleLowerCase()
	if (ua.indexOf('iphone') >= 0 || ua.indexOf('ipad') >= 0) {
		console.log('当前为iphone/ipad')
		$("#iphone").trigger("click");
	} else {
		console.log('当前为安卓');
		$("#other").trigger("click");

	}
</script>

</html>